I believe these anti-balloon flak wagons were used in Cambrai to stop advancing British Tanks. Photo caption - A German Kraftwagengeschütz in a repair shop, possibly post WW1. Presumably, a 7.7 cm anti-balloon cannon, perhaps or a 7.62 cm cannon (flak). The name "KRAFTW" on the bonnet. Business. K 48 ", certainly the number within the unit. On the front fender on the left a sign with the license plate "str. 165".The vehicle is partially armoured and some parts are missing, including the foldable loading lifts over the rear to widen the range of motion to the operation of the cannon.

Great photo!
a couple of things I noticed in the translation. I think the following chnges are in order
KRAFTW stands for Kraftwagen, translated as something as motor vehicle.
The translation for Gesch. is in this case not Business but Gun (Geschutz).
Thanks for sharing,
best regards,
Willem

Your foto depicts an Ehrhardt platform lorry armed with a Rhienmetall 7,7 cm BAK. The system was 4-wheel drive, and served as a companion to the more numerous Daimler version which was armed with the Krupp 7,7cm gun.

Your suggestion they were used at Cambrai is quite correct. Known kills of just 12 batteries (2 guns @ batterie) accounted for no less than 65 MkIVs. Their mobility allowed them to speed from locations in Caudry, Arras, & Busigny to converge on the break-through zone.

I've attached another pic of the Ehrhardt vehicle from the rear oblique.